Checker block and checker construction made therefrom



S. P. KINNEY Nov. 30, 1965 CHECKER BLOCK AND CHECKER CONSTRUCTION MADE THEREFROM 2 Sheets-Sheet 1 Filed Feb. 6. 1964 1 lgji ATTORNEYS.

' Nov. 30, 1965 P, KINNEY 3,220,115

CHECKER BLOCK AND CHECKER CONSTRUCTION MADE THEREFROM Filed Feb. 6, 1964 2 Sheets-Sheet 2 mm mm m 53 53 INVENTOR.

SELWYNE. P. KINNEY. "E 1 .4-. BY

ATTOR N EYS United States Patent 3,226,715 CHECKER BLOCK AND CHECKER CONSTRUC- TION MADE THEREFROM Selwyne P. Kinney, Crafton, Pa., assignor to S. P. Kinney Engineers, Inc, Carnegie, Pa., a corporation of Pennsylvania Filed Feb. 6, 1964, Ser. No. 342,915 5 Claims. (Cl. 263-51) This invention is for checker blocks for use in heat exchange structures such as blast furnace stoves and similar structures in which gases are alternately passed through a checker work of bricks or blocks to extract heat from the gas and then other gas is passed therethrough to be heated by contact with the brick.

The checker blocks of the the present invention are designed primarily for use in blast furnace stoves and will be particularly described in that connection, but they are not limited to such use. However, in blast furnace stoves unusually severe conditions exist because of the high temperatures involved, the alternate heating and cooling, and the massive character of the structure where blocks lower down in the structure are subjected to the great weight of the superposed checker work. These stoves are, of course, familiar structures in blast furnace plants and are used to heat the air blast for the furnace burners. On the firing part of the cycle, gas and air are burned in a combustion chamber and the hot combustion gases flow down through the checker work, heating it to a high temperature, and the gases exit through the bottom. In the air heating cycle air flows up through the checker work and out through the combustion chamber, being thereby intensely heated as it flows through the hot brick work. Consequently checker structure must be open to the vertical flow of gases therethrough.

In such structures the ratio of brick volume to area exposed to contact with the gases is an important consideration. Needless mass of brick is useless if the gases cannot contact it effectively, and heat is neither rapidly carried from the surface to the interior of a block or brick, nor does it flow rapidly from the interior to the surface for heaing the cold gases. Consequently the efiiciency or" the checker work for heat exchange purposes depends largely on the relation of surface exposed to contact with the heating or cooling gases to the cubical volume of the solids. At the same time, the air flow must be divided into small streams to intimately sweep against the exposed surfaces. However, the passages may not be so small as to offer too much resistance to the fiow of air or gases therethrough. The solid dimensions, on the other hand, must be strong enough to sustain a heavy weight at high temperatures.

In addition to all other factors, the bricks or blocks must be of a shape that can be produced economically. To have an otherwise effective shape would be of no value if each piece had to be shaped by hand on a potters wheel or some similar manner of individual hand crafting. Likewise, the checker blocks or bricks must be capable of being constructed rapidly, since the down time of a stove may impair the output of the blast furnace plant.

Recognizing that the volume of checker brick is limited by the size of the stove, many forms of checker brick or blocks have been designed and used in an endeavor to combine all of the factors so as to have large exposed areas of refractory with adequate strength; numerous air passages without excessive resistance to air flow; contours that can be made in block-forming apparatus without excessive loss through the forming of defective blocks; structures that can be put in place and still stand up without distortion. While some effective checkers are used Where the checker construction provides spacing ice between horizontal courses in a manner such that vertical flue passages in the structure communicate horizontally, some operators prefer checkers which provide only vertical flue passages, and the present invention pertains to such a checker construction.

The present invention has for its object to provide a block and checker work which can be manufactured in conventional manner, which can be easily handled and installed, which are designed to be placed one on top of another in contacting vertical columns, and which, while having good mechanical strength, have a large amount of exposed surface for the cubical content of the solid. Moreover, it will withstand the drastic heating and cooling for long periods of time without breakdown or distortion.

My invention may be more fully understood by reference to the accompanying drawings, in which:

FIG. 1 is a plan view of a single checker block with portions of adjacent blocks;

FIG. 2 is an isometric view of a position of the bottom of the checker bricks, illustrating the stacking of the bricks to break joints horizontally;

FIG. 3 is a fragmentary section through a portion of a blast furnace stove indicating the placement of the blocks in a stove; and

FIG. 4 is a plan view of a modified block of larger size.

Referring to the drawings, the blocks are desirably square. They are made in two lengths, one of which is twice the length of the other, the shorter blocks being placed alternately beside the longer ones at the bottom in order that the horizontal joints will break or be staggered in adjacent columns or tiers, and similarly the short lengths will be alternated beside the longer ones at the top to make the top of the checker work come out level. Therefore most of the blocks are the longer ones ande are designated 2, and the shorter ones, which are identical except for length, are designated 2a in. FIG. 2

The blocks have equidistantly-spaced flue passages extending longitudinally therethrough. These are designated generally as 3, and they are arranged in a square pattern. Each flue passage in section is of the shape shown, being generally in the form of a smaller square defined by the fiat walls 4 placed centrally within the corners 5 of alarger square, so that on each of the four sides there is a wide flat wall 4 defining a rib with sides 6. The side terminates in a corner-forming flat wall 7, the-fiat Walls 7 at each corner intersecting. This forms a generally right triangular space indicated by the dotted line aa in FIG. 1, the sides of which are defined by the flat walls 7, and the hypotenuse of which would be a line extending from the base 6 of one rib to the base 6 of the adjacent rib at right angles thereto, in other words, the dotted line aa.

efined another way, the opening is generally in the form of a square with the side of the square at the said portion depressed by the protruding rib surface 46.

The thickness of the outer walls of the blocks where they parallel the flue openings, i.e., the dimensions bb and cc in FIG. 1, is half the thickness of the walls between adjacent openings, i.e., the dimension of d.d in FIG. 1, whereby the combined solid wall section between any two adjacent blocks vertically forms a column identical in size and shape to the solid wall section between any two adjacent lines within a single block.

In the checker work structure it is desirable to obtain as low a ratio of weight of brick in pounds to square feet of heating surface as is possible. With presently available structures, it has been found in the steel industry that a ratio of about 10 is the minimum that can be obtained. Below this structural difliculties are encountered and walls that are too thin result in structural failures, and very much above this there is a useless volume of brick that reduces the available heating surface. While this may vary in individual bricks due to different densities of refractories used in different levels, the blocks of the present invention proportioned as shown will give an average of around 85.6 lbs. per cubic foot with a heating surface of 10.24 sq. ft. per cubic foot of brick for a ratio of about 8.35, thus substantially lowering the previously-obtainable minimum ratio of without sacrificing structural strength. This gain arises out of the fact that if square flue openings Were provided of the minimum dimension defined by the inner sides 4, the ratio of surface to volume would be lower, and if it were provided by a square of the dimension formed by projecting the fiat walls 7 to eliminate the ribs 4, the average wall thickness would be reduced too much. However, applicant has recognized that where four blocks come together, there is a solid column of brick much greater than is demanded for structural purposes. smaller square with the corners of a larger square, he eliminates that needless extra weight of solid brick in this column where four bricks adjoin and gains the additional heating surface provided by sides 6 of the ribs 4 and the longer fiat corner-forming sides 7. The same condition prevails not only Where four blocks adjoin, but also between any four fiues in the same block. The diagonal dimension of solid brick between any two diagonally-disposed fiue openings is equal to the distance between the fiat sides 4 of any two adjacent openings. In the assembled check, the wall structure formed by the combined walls of two adjacent blocks is the counterpart in shape and dimension to the internal wall structure between fiues in the individual blocks.

For purposes of illustration, I have placed dimensions on FIG. 1 for the purpose of better illustrating how the ratios above mentioned are derived in a block for use in blast furnace stoves. In some other form of heat regenerator used in a different environment, these dimensions would not be necessarily followed and the invention is not restricted thereto.

While a square block with four holes is considered by me as best for commercial manufacture and use, FIG. 4 shows on a smaller scale a block having a greater number of openings, but corresponding reference numerals are used to indicate the corresponding parts. Also, my invention may be incorporated into blocks of elongated rectangular shape, as distinguished from a square rectangle or right-angle parallelogram.

In FIG. 3 I have shown how the blocks are employed in a blast furnace stove. This is a typical stove having a shell 10, a combustion chamber 11, and a ring wall 12 of solid refractory blocks around the checker chamber. These are set in offset formation to form a pilastered interior. While only a few of the columns of blocks 2 are shown in FIG. 3, showing how they are fitted against the ring Wall, so that the checker Work is prevented from twisting about a vertical axis, as so often happens with many shapes of bricks, the entire interior of the checker chamber is filled with similar columns as indicated by the dotted squares. By using square blocks instead of rectangles, cutting of the blocks can be avoided by constructing the ring wall to provide a chamber that will accept even multiples of square blocks in each direction, and the bricklayer can install the checker simply by placing one on top of another. In either FIG. 1 or FIG. 4 there is a flue opening in each corner of the block and the openings are arranged side by side in each direction from one corner to the next.

The checkers are of course formed of refractories commonly used in the art, and the shape is such that the plastic refractory mix can be formed in conventional block-forming machinery simply by providing proper dies.

Therefore, by combining the sides of a 1 I claim:

1. A checker block comprising a right-angle parallelogram with flat side walls, the block also having fiat end faces, a plurality of openings extending through the block rom one end face to the other, there being one such opening in each corner of the block with the openings being arranged in side-by-side formation from each corner in each direction to the adjacent corner, said openings each having four sides in planes parallel with the sides of the block and forming portions of an incomplete inner square and corner portions constituting corners of an incomplete concentric outer square whereby the opening has four fiat side walls in the nature of a thickened rib portion and corners of generally right-triangular shape, the hypotenuse of which would be defined by a line extending from the base of one rib to the base of the next rib in the opening at right angles to the first.

2., A checker block as defined in claim 1 wherein the right-angle parallelogram is a square.

3. A checker block as defined in claim 1 wherein there is a partition between the side walls of adjacent openings, the thickness of which at any point is twice the thickness from a corresponding point in a corner opening to the outside wall of the block whereby when two such blocks are placed side by side the combined thickness of the walls of the two adjacent blocks correspond in thickness and in contour to the partition separating any two openings which are side by side.

4. A checker construction for blast furnace stoves and the like comprised of blocks as defined in claim 1 placed in vertical columns end on end with the blocks in one column being in contact with the blocks of the surrounding columns.

5. A checker construction comprised of square blocks stacked end-on-end into columns with the individual columns being surrounded with similar columns in side-toside contact, the blocks of all of the columns being of similar section with each having four flat side walls and each having flat end faces, each block having a plurality of openings extending therethrough from one end face to the other, there being one opening in each corner of the block with the openings being arranged in side-by-side formation from each corner to the adjacent corners, each opening having four sides in planes parallel with the sides of the block, these sides forming the side portions of an incomplete square, each opening having corner portions constituting corners of an incomplete concentric outer square whereby the opening has four flat side walls in the nature of a thickened rib portion and recessed corners of generally right-triangular shape, the hyptotenuse of which would be defined by a line extending from the base of one rib to the base of the next rib in the opening at right angles to the first, the blocks having solid partitions between the openings which are twice the thickness at any point of the corresponding thickness of the side wall of the block from a corner opening to a side face of the block whereby the combined thicknesses of the walls of two columns in the checker work which are in face-to-face contact are approximately the same in shape and contour as the thickness and shape and contour of the partition within any one block between two side-byside openings.

References Cited by the Examiner UNITED STATES PATENTS 2,034,820 3/1936 McDonald 26351 2,172,714 9/1939 Schack et al 263-51 FOREIGN PATENTS 1,179,266 12/1958 France.

CHARLES SUKALO, Primary Examiner.

JOHN J. CAMBY, Examiner. 

1. A CHECKER BLOCK COMPRISING A RIGHT-ANGLE PARALLELOGRAM WITH FLAT SIDE WALLS, THE BLOCK ALSO HAVING FLAT END FACES, A PLURALITY OF OPENINGS EXTENDING THROUGH THE BLOCK FROM ONE END FACE TO THE OTHER, THE RE BEING ONE SUCH OPENING IN EACH CORNER OF THE OTHER, THERE BEING OE SUCH BEING ARRANGED IN SIDE-BY-SIDE FORMATION FROM EACH CORNER IN EACH DIRECTION TO THE ADJACENT CORNER, SAID OPENINGS EACH HAVING FOUR SIDES IN PLANS PARALLEL WITH THE SIDES OF THE BLOCK AND FORMING PORTIONS OF AN INCOMPLETE INNER SQUARE AND CORNER PORTIONS CONSTITUTING CORNERS OF AN INCOMPLETE CONCENTRIC OUTER SQUARE WHEREBY THE OPENING HAS FOUR FLAT SIDE WALLS IN THE NATURE OF A THICKENED RIB PORTION AND CORNERS OF GENERALLY RIGH-TRIANGULAR SHAPE, THE HYPOTENUSE OF WHICH WOULD BE DEFINED BY A LINE EXTENDING FROM THE BASE OF ONE RIB TO THE BASE OF THE NEXT RIB IN THE OPENING AT RIGHT ANGELES TO THE FIRST. 